<template>
  <div class="xtx-carousel" @mouseenter="stop()" @mouseleave="start()">
    <ul class="carousel-body">
      <li class="carousel-item " v-for="(item,index) in sliders" :key="item.id"
:class="{fade:activeindex===index}"
       >
        <RouterLink  v-if="item.imgUrl" :to="item.hrefUrl">
          <img
            v-src="item.imgUrl"
            alt=""
          />
        </RouterLink>
         <!-- 情况2：同类推荐和猜你喜欢 -->
        <div v-else class="slider">
          <RouterLink
            v-for="goods in item"
            :key="goods.id"
            :to="`/product/${goods.id}`"
          >
            <img :src="goods.picture" alt="" />
            <p class="name ellipsis">{{ goods.name }}</p>
            <p class="price">&yen;{{ goods.price }}</p>
          </RouterLink>
        </div>
      </li>
    </ul>
    <a @click="toggle(-1)" href="javascript:;" class="carousel-btn prev">
      <i class="iconfont icon-angle-left"></i>
    </a>
    <a @click="toggle(1)" href="javascript:;" class="carousel-btn next">
      <i class="iconfont icon-angle-right"></i>
    </a>
    <!-- //控制器 -->
    <div class="carousel-indicator">
      <span v-for="(i,index) in sliders" :key="i.id"
      @click="activeindex=index"
:class="{active:activeindex===index}"
      ></span>
    </div>
  </div>
</template>

<script>
import { onUnmounted, ref, watch } from 'vue'
export default {
  name: 'XtxCarousel',
  props: {
    sliders: {
      type: Array,
      default: () => []
    },
    duration: {
      type: Number,
      default: 3000
    },
    autoPlay: {
      type: Boolean,
      default: false
    }
  },
  setup (props) {
    const activeindex = ref(0)
    // 点击方法轮播图
    const toggle = Number => {
      // 定义临时变量记录加一或者减一
      const teep = activeindex.value + Number
      //   临时变量小于0
      if (teep < 0) {
        //   数组长度减一
        activeindex.value = props.sliders.length - 1
        // 临时变量大于数组长度减一
      } else if (teep > props.sliders.length - 1) {
        // 就让数组变成0
        activeindex.value = 0
      } else {
        activeindex.value = teep
      }
    }
    // 定义一个id，来记录当前的定时器的下标 就是当前定时器轮播到那个图片
    let timeId = null
    // 给一个函数
    const autoplayFn = () => {
      // 进来清除定时器
      clearInterval(timeId)
      // 定时器
      timeId = setInterval(() => {
        toggle(1)
      }, props.duration)
    }
    // 判断数组的长度和数组是不是在轮播 然后调用上面的方法
    if (props.sliders.length > 1 && props.autoPlay) {
      autoplayFn()
    }
    watch(() => props.sliders, (val) => {
      // 超过一张图片 并且 传递了 autoPlay 开启自动播放，才调用自动播放函数
      if (val.length > 1 && props.autoPlay) {
        autoplayFn()
      }
    }, { immediate: true })
    // 组件卸载，需要清理定时器
    onUnmounted(() => {
      clearInterval(timeId)
    })
    // 鼠标进入停止，移出开启自动，前提条件：autoPlay为true
    const stop = () => {
      if (timeId) clearInterval(timeId)
    }
    const start = () => {
      if (props.sliders.length && props.autoPlay) {
        autoplayFn()
      }
    }

    return { activeindex, toggle, stop, start }
  }

}
</script>

<style scoped lang="less">
.xtx-carousel {
  width: 100%;
  height: 100%;
  min-width: 300px;
  min-height: 150px;
  position: relative;
  .carousel {
    &-body {
      width: 100%;
      height: 100%;
    }
    &-item {
      width: 100%;
      height: 100%;
      position: absolute;
      left: 0;
      top: 0;
      opacity: 0;
      transition: opacity 0.5s linear;
      &.fade {
        opacity: 1;
        z-index: 1;
      }
      img {
        width: 100%;
        height: 100%;
      }
    }
    &-indicator {
      position: absolute;
      left: 0;
      bottom: 20px;
      z-index: 2;
      width: 100%;
      text-align: center;
      span {
        display: inline-block;
        width: 12px;
        height: 12px;
        background: rgba(0, 0, 0, 0.2);
        border-radius: 50%;
        cursor: pointer;
        ~ span {
          margin-left: 12px;
        }
        &.active {
          background: #fff;
        }
      }
    }
    &-btn {
      width: 44px;
      height: 44px;
      background: rgba(0, 0, 0, 0.2);
      color: #fff;
      border-radius: 50%;
      position: absolute;
      top: 228px;
      z-index: 2;
      text-align: center;
      line-height: 44px;
      opacity: 0;
      transition: all 0.5s;
      &.prev {
        left: 20px;
      }
      &.next {
        right: 20px;
      }
    }
  }
  &:hover {
    .carousel-btn {
      opacity: 1;
    }
  }
  // 轮播商品
  .slider {
    display: flex;
    justify-content: space-around;
    padding: 0 40px;
    > a {
      width: 240px;
      text-align: center;
      img {
        padding: 20px;
        width: 230px !important;
        height: 230px !important;
      }
      .name {
        font-size: 16px;
        color: #666;
        padding: 0 40px;
      }
      .price {
        font-size: 16px;
        color: @priceColor;
        margin-top: 15px;
      }
    }
  }
}
</style>
